Lock for sectional scaffolding



Jan. 24, c S U LOCK FOR SECTIONAL SCAFFOLDING Filed June 9, 1964 INVENTOR.

United States Patent F 3,300,236 LOCK FOR SECTHONAL SCAFFOLDING Clyde Sauls, 824 Hertel Ave, Bufialo, N.Y. 14216 Filed June 9, 1964, Ser. No. 373,757 Claims. (Cl. 28753.5)

This invention relates to sectional scaffold frame brace bar locks.

Scaffolds of the type to which this invention relates which are built up to monumental heights and are composed of a plurality of vertical cross structures or standards connected together on opposite sides by pairs of diagonal brace bars which cross each other and have their opposite ends removably connected to the upper and lower extremities of the vertical cross structures or standards. Such scaffolding is built up by fitting the bottoms of one row of the vertical cross structures or standards onto the tops of the next lower row and applying the diagonal brace bars thereto. The present invention relates to the lock or latch for detachably securing the ends of the diagonal brace bars to the upper and lower extremities of the vertical cross structures or standards.

One of the principal objects of the present invention is to provide such a lock or latch which is strong and rugged in construction so as to be safe for use in such scaffolding built up to great heights and which also forms a firm and positive connection between each diagonal brace bar and its vertical cross structures or standards so that the scaffolding as a whole is free from sleaziness or movement due to play in the connections between the diagonal cross bars and the vertical cross structures or standards.

Another important object of the present invention is to provide such locks which in use tend to tighten or wedge themselves into a condition providing firmer and more positive connections between the diagonal cross bars and the vertical cross structures or standards as compared with locks which tend to work themselves loose and provide increasing play at these joints.

Another object is to provide such a lock all parts of which are permanently attached to the vertical cross structures or standards of the scaffolding to avoid danger of accidental loss of any of the parts and so that in erecting the scaffolding all parts of the lock or latch are immediately available for use once the diagonal brace bars have been positioned.

Another object of the invention is to provide such a latch or look which so tightens or wedges itself into a condition providing firmer engagement between the latched parts regardless of whether the latch or lock is serving one, two, or more than twodiagonal brace bars.

Another object of the invention is to provide such a lock or latch which can be readily moved to release the latched diagonal brace bars but which requires a special manual manipulation to effect such release so that accidental release, such as being dislodged by one climbing the diagonal bars, is minimized.

Another object is to provide such a lock or latch including elements fixed to the vertical cross structures or standards in such manner as not to weaken either the cross structures or the elements.

Another object is to provide such a lock or latch the component parts of which can be produced at low cost and also assembled at low cost.

Other objects and advantages of the invention will be apparent from the following description and drawings in which:

FIG. 1 is a fragmentary perspective view of the bottom course of scaffolding having vertical cross structures or standards connected by diagonal brace bars by means of locks or latches embodying the present invention.

FIG. 2 is a greatly enlarged vertical fragmentary sec-. tion taken generally on line 2-2 of FIG. 1:

3,300,236 Patented Jan. 24, 1967 FIG. 3 is -a further enlarged fragmentary horizontal section taken generally on line 33 of FIG. 5.

FIG. 4 is a fragmentary vertical section taken generally on line 44 of FIG. 2 illustrating the lock or latch in position for receiving the diagonal brace bars.

FIG. 5 is a similar view illustrating the diagonal brace bars mounted on a lower stud and the movable lock or latch member partially in place for locking the same.

FIG. 6 is a similar view illustrating the movable lock or latch member in its fully operative position.

FIG. 7 is a similar view illustrating the position the movable member of the lock or latch member would assume it an upward force were applied in the direction of the arrow shown, and illustrating that the movable latch member would not be displaced from its operative position.

FIG. 8 is a similar view illustrating the position the movable lock or latch member would assume if a horizontal outward force were applied in the direction of the arrow illustrated to the bottommost part thereof, and showing that this movable lock or latch member would not be displaced from its operative position.

The lock or latch of the present invention is illustrated in conjunction with conventional tubular scaffolding now in common use arid erected for great lengths and to monumental heights in the building industry. This conventional scaffolding is shown as comprising a plurality of conventional vertical cross structures or standards 10 each comprising a pair of spaced vertical tubular uprights 11 secured together in parallel relationship by horizontal tubular cross bars 12 and a center vertical tubular upright 13, with or without an associated horizontal cross bar member 14 extending from one of the tubular uprights 11 to the tubular center upright 13. The bottom course of thescaffolding is illustrated in FIG. 1 and each tubular upright 11 is shown as having a base plate '15 fixed thereto and as .having avreduced upper end 16 adapted to fit into the socketed bottom of a tubular upright 11 of the next succeeding higher course (not shown).

The upper and lower end of each of the tubular up-- rights 11 are provided witha lock or latch 17 embodying the present invention. Each of these locks or latches are adapted to connect with one or more diagonal brace bars 18 which cross each other in the manner illustrated in FIG. 1 to provide the diagonal bracing for the scaffold. Each of these diagonal brace .bars is shown as being in =the form of an angle bar with one flange folded at each end in face-to-face relation against its other flange to provide flattened ends 19 at the opposite ends of the diagonal brace bars 18 and these flattened ends 19 being provided with at transverse hole 21 extending through both flanges.

Each latch or lock 17 embodying the present invention comprises pairs of upper and lower studs 22, 23 welded or otherwise'fixed to the upper and lower ends of each tubular upright 11 to project horizontally inwardly therefrom parallel with the tubular cross bars 12 so that these studs 22, 23 are on the inner sides of the vertical structures or standards 10 and project in opposed relation to one another.

The upper stud 22 is provided with a longitudinal slot 24 extending vertically therethrough and extending outwardly from its inboard end short of its outboard extremity so as to provide an abutment or stop 25 for the slot at the outboard end of the stud. The inboard end of the stud projects through a hole 26 provided in the companion tubular upright 11 and is welded in position, preferably .by an internal weld 27. The face 28 of the abutment 25 whichopposes the corresponding tubular upright 11 is preferably vertical and terminates in an upper corner or edge 29 for a purpose which will presently appear.

The lower stud 23 is provided with a longitudinal slot 30 extending vertically therethrough and extending outwardly from its inboard end short of its outer extremity so as to leave a stop or abutment 31 which terminates the outer end of this slot. This abutment preferably has a vertically inclined inner face 32, this face preferably being planar and inclining upwardly and outwardly. The inboard end of each stud 23 extends through a hole 33 provided in the corresponding tubular upright 11 and is welded thereto, preferably by an internal weld 34.

The slots 24 and 30 are of the same width and are preferably provided with parallel vertical sides, and these parallel vertical sides of the lower stud 23, indicated at 35, are provided with upwardly inclining grooves 36 Which are open at their upper and lower ends and arranged opposite and parallel to each other. Preferably these grooves extend at an angle, extending upwardly and outwardly at a slightly lesser angle than the face 32 forming the end face of the compansion slot 30.

The movable element of the lock or latch of the present invention is in the form of a vertical wedge plate 40 having a thickness slightly less than the slots 24 and 3-0 and slidingly fitted therein so as to be capable of movement in all directions in the plane of the pair of slots 24, 30 but incapable of being turned to any substantial extent about a vertical or horizontal axis. This wedge plate 40 is of wedge-shaped form in side elevation having an inner vertical edge 41 adapted to be brought into closely spaced parallel relation with the corresponding tubular upright 11, a second edge 42 extending upwardly and outwardly from the lower end thereof at an inclined angle of about 20, and a top provided with a transversely eX- tending flange 43 which is positioned horizontally when the edge 41 is positioned vertically and which prevents the wedge plate from dropping into the slot 24 and also facilitates lifting or withdrawing the plate 40 as hereinafter described. Each latch or lock 17 is completed by at least one of a pair of bead-like protuberances 44 which are preferably generally of semispherical form projecting outwardly from the opposite vertical flat sides of each wedge plate 40 in axial alinement with each other. These protuberances are arranged close to the lower pointed extremity of the wedge plate 40 and are of a size capable of entering and passing vertically through the grooves 36 provided in the side faces 35 of the slot 30 through the lower stud 23.

The effective length of the lower stud 23 and its slot 30 is such that the flattened ends 19 of a number of diagonal brace bars 18, say three or four, can be threaded thereon and still permit the lower pointed end of the wedge plate 40 to be passed downwardly through its slot 30 to a position where the protuberances 44 thereof are arranged below the bottom of the lower stud 23.

In erecting scaffolding having locks or latches embodying the present invention, the cross structures or standards are held upright in properly spaced relation to each other and to the structure under construction and the ends of the diagonal brace bars 18 fitted on the lower studs 23. This fitting of these diagonal brace bars is effected by positioning their end holes 21 in line with the ends of the lower studs 23 and moving the studs horizontally so that these lower studs project through these holes. Such fitting is permitted by lifting the wedge plates 40 to the inoperative position shown in FIG. 4. This is done by lifting each wedge plate vertically and then swinging the plate outwardly so that its protuberances 44 engage the bottom edges of the slot 24 of the upper stud 22 and so that its edge 42 engages and rests onthe edge or corner 29 of the end abutment 25 of the slot, the plate being of suflicient length so that its center of gravity at this time is outboard of the edge or corner 29 and so'that the plate rests in the inoperative angular position illustrated in FIG. 4. One, two, three or more flattened ends 19 of the diagonal brace bars can be threaded on any one lower stud 23. Thus, in the structure illustrated in FIG. 2', each lower stud 23 projects through the flattened ends 19 of two diagonal brace bars 18 and could project through more if required under special circumstances.

After the flattened ends 19 of one or more diagonal brace bars 18 have been fitted over each lower stud 23, the corresponding wedge plate 40 is manually moved to its operative position. This manipulation of each wedge plate 40 involves swinging it about the edge 29 of the abutment 25 terminating the outer end of the slot 24 of the upper stud 22 and at the same time swinging it to bring its edge 41 to a generally upright position and drawing it downwardly so that its pair of protuberances 44 are brought to a position above the slot 30 of the companion lower stud 23. The lower end of the wedge plate 40 is then moved along this slot 30 until the pair of protuberances 44 are brought into alinement with the open upper ends of the grooves 36 in the vertical side faces 35 of the slot 30. The wedge shaped plate 40 is then moved downwardly in the direction to cause its protuberances 44 to move downwardly along these grooves 36 and to emerge from the lower ends thereof.

The wedge plate 40 is then moved downwardly so that its edge 41 is brought into pressure contact with the flattened end 19 of the outermost diagonal brace bar 18 and so that its edge 42 is brought into pressure contact with the inclined end face 32 of the slot 30 of the lower stud 23. This pressure contact preferably that resulting from merely manually pressing the plate 40 down and pushing the flattened faces 19 of the corre= sponding diagonal brace bars 18 against their tubular upright 11, it being unnecessary to use any tool, such as a hammer or the like, to drive the wedge plate down= wardly. Indeed, even if the workman should fail to obtain a snug pressure fit of the flat ends 19of the diagonal brace bars 18 against the tubular upright 11 and the edge 41 of the wedge plate, the subsequent movement and vibration of the scaffolding in use will cause the wedge plates 40 to settle down and automatically effect s-uch pressure contact.

An important feature of the invention is that each lock or latch 17 is prevented from being accidentally rendered inoperative under almost any circumstances, such as workmen climbing the diagonal brace bars 18 or an underside of any of the wedge plates being struck or pressed upwardly. When this occurs, the protuberances 44 merely come into engagement with the bottom edges of the slot 30 of its lower stud 23 and serve as stops to prevent further upward movement of the wedge plate and possible accidental release of the flattened ends 1 thereon. However, the wedge plates 40 can be deliberate ly lifted to the original inoperative position assumed by a particular manual manipulation thereof Which in= volves not merely lifting the same but also moving the plate in a particular path while being so lifted. Thus, in taking down the scaffolding, in order to permit the withdrawal of the flattened ends 19 of the diagonal brace bars 18 from any particular lower stud 23, the workman lifts the corresponding wedge plate 40 and can initially use a tool applied under the horizontal top flange 43 for this purpose, if necessary. While so lifting the wedge plate 40 he swings the lower end thereof along its lower stud 23 so as to position its pair of protuberances 44 in line with the lower ends of the pair of grooves 36 in the side walls 35 of the slot 30 in this lower stud 23. He then continues lifting the wedge plate 40 and in so doing the lower end of the wedge plate is guided to swing further outwardly away from the tubular upright 11 'by virtue of the upward and outward inclination of the grooves 36.

When the protuberances 44 emerge from the upper ends of the opposed grooves 36, the wedge plate 40 is free to be lifted until its protuberances 44 come into engagement with the lower edges of the slot 24 of the upper stud 22 at which time the workman swings the upper end of the wedge plate 40 horizontally outwardly until its edge 42 engages the upper edge 29 of the abutment 25 of the upper stud 22. When this occurs the center of gravity of the wedge plate is disposed horizontally outwardly beyond this edge 29 so that the wedge plate retains this inoperative position, as illustrated in FIG. 4, and the workman can remove the flattened ends 19 fitted onto the lower stud 23 thereby to restore the parts to the condition assumed at the start of this description of operation.

From the foregoing it will be seen that the present invention accomplishes the various objectives previously set forth, particularly in providing a lock or latch including a wedge plate which not only adapts the lock or latch to the securement of one, two, three or more diagonal brace bars but also tends to secure them more firmly as the scaffolding is used and subjected to vibration which causes the wedge plates to settle. Also it will be seen that the pressure contact efi'ected by this wedge plate is positive, and sleaziness of the scaffolding structure as a whole is avoided by virtue of the fact that play between the vertical cross structures and diagonal brace bars 18 is minimized. Also it will be noted that accidental release of any wedge plate is avoided by virtue of the presence of the protuberances 44 and opposed grooves 36 which require a particular and deliberate manual manipulation of the wedge plate in releasing the same and which is not likely to occur accidentally. The same protuberances also prevent the wedge plate from being withdrawn from the slot of the upper stud and serve to support it in the inoperative position shown in FIG. 4 while the diagonal brace bars are being positioned or removed.

I claim:

1. In a scaffold having an upright and a diagonal brace bar provided with a hole through one end thereof; the combination therewith of a latch for releasably locking said end of said diagonal brace to said upright, comprising an upper stud fixed to and projecting generally horizontally from said upright and provided with a longitudinal slot extending vertically therethrough and having generally parallel fiat vertical longitudinal side faces, an abutment across and terminating the outboard end of said slot, a lower stud fixed to and projecting generally horizontally from said upright in spaced generally parallel relation directly below said upper stud and provided with a longitudinal slot extending vertically therethrough in vertical alinement with said slot through said upper stud, an abutment across and terminating the outboard end of said slot through said lower stud, said end of said diagonal brace bar fitting on said lower stud with said lower stud projecting through and beyond the hole therethrough, a wedge plate fitting in both of said slots in closely fitted relation to said side faces of said slot through said upper stud and having a first edge adapted to be brought into pressure contact with said end of said brace bar fitted on said lower stud, and having a second edge extending upwardly from the lower end of said first edge at an acute included angle relative thereto and in pressure contact with said abutment of said lower stud, said second edge also engaging said abutment of said upper stud, and a protuberance on the lower end of said wedge plate projecting horizontally therefrom and rendering said wedge plate larger, in a horizontal direction, than the corresponding dimension of said slot through said upper stud but less than the corresponding dimension of said slot through said lower stud whereby said wedge plate can be withdrawn upwardly from said lower stud but cannot be withdrawn upwardly from said upper stud.

2. In a scaffold having an upright and a diagonal brace bar provided with a hole through one end thereof; the combination therewith of a latch for releasably locking said end of said diagonal brace to said upright, comprising an upper stud fixed to and projecting generally hori- 'zontally from said upright and provided with a longisaid end of said diagonal brace bar fitting on said lower stud with said lower stud projecting through and beyond the hole therethrough, a wedge plate in closely fitted relation to said side faces of both of said slots and having a first edge adapted to be brought into pressure contact with said end of said brace bar fitted on said lower stud, and having a second edge extending upwardly from the lower end of said first edge at an acute included angle relative thereto and in pressure contact with said abutment of said lower stud, said second edge also engaging said abutment of said upper stud, and a protuberance on said wedge plate engaging a bottom edge of said upper stud and preventing upward withdrawal of said wedge plate from said s-lot through said upper stud, said wedge plate being of sufiicient length, lengthwise of its said edges, that when said protuberance engages said bottom edge of said upper stud and said second edge of said wedge plate is brought into engagement with the upper edge, facing said upright, of said abutment of said upper stud, the center of gravity of said wedge plate is outboard of a vertical plate, transversely of said upper stud, intersecting the outboard end of said slot through said upper stud, whereby said wedge plate is supported in an inoperative position by gravity exclusively by said upper stud and in spaced relation above said lower stud.

3. In a scaffold having an upright and a diagonal brace bar provided with a hole through one end thereof; the combination therewith of a latch for releasably locking said end of said diagonal brace to said upright, comprising an upper stud fixed to and projecting generally horizontally from said upright and provided with a longitudinal slot extending vertically therethrough and having generally parallel flat vertical longitudinal side faces, an abutment across and terminating the outboard end of said slot, a lower stud fixed to and projecting generally horizontally from said upright in spaced generally parallel relation directly below said upper stud and provided with a longitudinal slot extending vertically therethrough in vertical alinement with said slot through said upper stud and having generally parallel flat vertical longitudinal side faces, an abutment across and terminating the outboard end of said slot through said lower stud, said end of said diagonal brace bar fitting on said lower stud with said lower stud projecting through and beyond the hole therethrough, a wedge plate in closely fitted relation to said side faces of both of said slots and having a first edge adapted to be brought into pressure contact with said end of said brace bar fitted on said lower stud, and having a second edge extending upwardly from the lower end of said first edge at an acute included angle relative thereto and in pressure contact with said abutment of said lower stud, said second edge also engaging said abutment of said upper stud, and a protuberance on said wedge plate engaging a bottom edge of said upper stud and preventing upward withdrawal of said wedge plate from said slot through said upper stud, one vertical longitudinal side wall of the slot in said lower stud being provided with a groove extending from the upper to the lower edges of said slot and forming a way receiving and permitting passage of said protuberance, whereby said wedge plate can only be inserted downwardly through and removed upwardly from the slot in said lower stud by manually and deliberately guiding said protuberance into and through said groove, thereby to minimize accidental displacement of said wedge plate from the slot of said lower stud.

4. The combination set forth in claim 3 wherein said protuberance is from a side face of said wedge plate adjacent the juncture of said first and second edges and wherein said groove is at the outboard end of the slot in said lower stud.

5. The combination set forth in claim 4 wherein the face of said abutment of said lower stud is at an angle to the vertical, inclining upwardly and outwardly, and

wherein said groove is at an angle to the vertical, also inclining upwardly and outwardly.

References Cited by the Examiner UNITED STATES PATENTS 1,506,442 8/1924 OHara. 2,017,626 10/1935 Kohnke. 2,526,529 10/ 1950 Arringhini et a1. 2,971,786 2/1961 May 28753.5 3,179,212 4/1965 Gostling 287-535 X CARL W. TOMLIN, Primary Examiner.

T A. LIS-LE, Assistant Examiner. 

1. IN A SCAFFOLD HAVING AN UPRIGHT AND A DIAGONAL BRACE BAR PROVIDED WITH A HOLE THROUGH ONE END THEREOF; THE COMBINATION THEREWITH OF A LATCH FOR RELEASABLY LOCKING SAID END OF SAID DIAGONAL BRACE TO SAID UPRIGHT, COMPRISING AN UPPER STUD FIXED TO AND PROJECTING GENERALLY HORIZONTALLY FROM SAID UPRIGHT AND PROVIDED WITH A LONGITUDINAL SLOT EXTENDING VERTICALLY THERETHROUGH AND HAVING GENERALLY PARALLEL FLAT VERTICAL LONGITUDINAL SIDE FACES, AN ABUTMENT ACROSS AND TERMINATING THE OUTBOARD END OF SAID SLOT, A LOWER STUD FIXED TO AND PROJECTING GENERALLY HORIZONTALLY FROM SAID UPRIGHT IN SPACED GENERALLY PARALLEL RELATION DIRECTLY BELOW SAID UPPER STUD AND PROVIDED WITH A LONGITUDINAL SLOT EXTENDING VERTICALLY THERETHROUGH IN VERTICAL ALINEMENT WITH SAID SLOT THROUGH SAID UPPER STUD, AN ABUTMENT ACROSS AND TERMINATING THE OUTBOARD END OF SAID SLOT THROUGH SAID LOWER STUD, SAID END OF SAID DIAGONAL BRACE BAR FITTING ON SAID LOWER STUD WITH SAID LOWER STUD PROJECTING THROUGH AND BEYOND THE HOLE THERETHROUGH, A WEDGE PLATE FITTING IN BOTH OF SAID SLOTS IN CLOSELY FITTED RELATION TO SAID SIDE FACES OF SAID SLOT THROUGH SAID UPPER STUD AND HAVING A FIRST EDGE ADAPTED TO BE BROUGHT INTO PRESSURE CONTACT WITH SAID END OF SAID BRACE BAR FITTED ON SAID LOWER STUD, AND HAVING A SECOND EDGE EXTENDING UPWARDLY FROM THE LOWER END OF SAID FIRST EDGE AT AN ACUTE INCLUDED ANGLE RELATIVE THERETO AND IN PRESSURE CONTACT WITH SAID ABUTMENT OF SAID LOWER STUD, SAID SECOND EDGE ALSO ENGAGING SAID ABUTMENT OF SAID UPPER STUD, AND A PROTUBERANCE ON THE LOWER END OF SAID WEDGE PLATE PROJECTING HORIZONTALLY THEREFROM AND RENDERING SAID WEDGE PLATE LARGER, IN A HORIZONTAL DIRECTION, THAN THE CORRESPONDING DIMENSION OF SAID SLOT THROUGH SAID UPPER STUD BUT LESS THAN THE CORRESPONDING DIMENSION OF SAID SLOT THROUGH SAID LOWER STUD WHEREBY SAID WEDGE PLATE CAN BE WITHDRAWN UPWARDLY FROM SAID LOWER STUD BUT CANNOT BE WITHDRAWN UPWARDLY FROM SAID UPPER STUD. 